The turtles face a new challenge when Shredder escapes from custody and joins forces with Baxter Stockman, a mad scientist who plans to use a serum to take over the world. Along for the ride are Bebop and Rocksteady, two dimwitted henchmen who provide plenty of muscle. Luckily, the turtles have their own allies in April O'Neil, Vernon Fenwick and the hockey-masked vigilante, Casey Jones. As the pizza-loving heroes prepare for battle, the notorious Krang also emerges to pose an even greater threat.